Method and Apparatus for Partially Submerged User Operation

ABSTRACT

An “in the water” user experience is provided. A device holds a user partially submerged in the water, and propels the user and device with the user partially submerged. The user and device together have a center of buoyancy, which can be adjusted to accommodate users of different size and weight. Thus, a user can be propelled through the water.

RELATED CASES

This application claims the benefit of priority of U.S. ProvisionalPatent Application No. 61/309,820, filed Mar. 2, 2010.

FIELD

Embodiments of the invention are generally related to water-bornedevices, and more particularly to a device that propels a user throughthe water.

COPYRIGHT NOTICE/PERMISSION

Portions of the disclosure of this patent document may contain materialthat is subject to copyright protection. The copyright owner has noobjection to the reproduction by anyone of the patent document or thepatent disclosure as it appears in the Patent and Trademark Officepatent file or records, but otherwise reserves all copyright rightswhatsoever. The copyright notice applies to all data as described below,and in the accompanying drawings hereto, as well as to any softwaredescribed below: Copyright © 2011, Don L. Cray, All Rights Reserved.

BACKGROUND

The popularity of water activities can be seen by observing the numerousdevices and crafts that have been designed for use in the water. Onepossibly grouping of water devices is based on functionality, such ascarrying a user over the water, or for use in the water. Carry a userover the water refers to generally moving the user over the waterwithout the user getting wet. Devices for use in the water are designedto be fully submerged, in contact with the water.

Examples of devices for carrying a user over the water may includeboats, canoes, paddle-boats, jet-skis, and other similar craft thatcarry a rider over the water, either for leisure or to arrive to alocation. Examples of devices for use in the water may include scubagear, submersibles (motorized craft that drag or drive a user fullysubmerged), and other similar devices intend for the user to be fullysubmerged, in contact with the water. Non-motorized devices may alsoinclude boogie boards, surf boards, personal flotation devices, tubes,and other devices. Non-motorized devices rely upon the user or the wavesor water movement to propel a user, or otherwise are intended more forstationary enjoyment of the water. Thus, there exist devices forenjoyment above the water as well as for under the water, but not formoving a user in the water.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description includes discussion of figures havingillustrations given by way of example of implementations of embodimentsof the invention. The drawings should be understood by way of example,and not by way of limitation. As used herein, references to one or more“embodiments” are to be understood as describing a particular feature,structure, or characteristic included in at least one implementation ofthe invention. Thus, phrases such as “in one embodiment” or “in analternate embodiment” appearing herein describe various embodiments andimplementations of the invention, and do not necessarily all refer tothe same embodiment. However, they are also not necessarily mutuallyexclusive.

FIG. 1 represents an embodiment of a device that carries a userpartially submerged in the water.

FIG. 2 represents an embodiment of a flotation portion of a device thatcarries a user partially submerged in the water.

FIGS. 3A-3B represent an embodiment of a front view of a device thatcarries a user partially submerged through the water, illustrating theseating portion and the propellers.

FIGS. 4A-4C represent an embodiment of a device that carries a userpartially submerged in the water, illustrating more detail with respectto battery mechanisms.

FIGS. 5A-5B represent an embodiment of a device that carries a userpartially submerged in the water, and having a water gun attachment.

FIGS. 6A-6B represent an embodiment of a device that carries a userpartially submerged in the water, and having an underwater viewingportion.

Descriptions of certain details and implementations follow, including adescription of the figures, which may depict some or all of theembodiments described below, as well as discussing other potentialembodiments or implementations of the inventive concepts presentedherein. An overview of embodiments of the invention is provided below,followed by a more detailed description with reference to the drawings.

DETAILED DESCRIPTION

As described herein, a self-powered device allows for an in-the-wateruser experience by moving a user partially submerged through the water.Thus, a user can enjoy “fun in the water”, being in the water while ableto move through the water rather than over the water, but withoutrequiring the equipment, training, or effort of using underwaterdevices. The device described herein allows the user to be partiallysubmerged, in contact with the water, and propelled along through thewater. As shown in more detail below, the device is able to adjust acenter of buoyancy of the combination of device-plus-user to adjust toindividuals of differing height and weight, while maintaining thefunctionality.

Thus, embodiments of the invention relate to devices and methods tocarry a user in the water, rather than above the water. The user ispartially submerged, rather than fully submerged. Partially submerged,as used herein, refers to a user being in the water with at least theuser's head above the surface of the water, and at least the user's legsbelow the surface of the water, during operation of the device. Thus,the partial submersion is by design, rather than incidentally havingsome part of the user submerge during use (e.g., such as on a Jet Ski orsimilar device—all trademarks used herein are the property of theirrespective owners, and are used herein only for purposes ofidentification). The partial submersion is also achieved in a devicethat is self-propelled to carry a user along in or through the water,instead of traditional simple boards or tubes.

The device described herein includes a mechanism to adjust the center ofbuoyancy of the device and user together. Considering the device and theuser together (device+user) to be a “system,” the mechanism can adjusthow a user sits in the water for using the device. In one embodiment,the adjustment mechanism includes an adjustable, extendable seat portionthat can be vertically adjusted with respect to the surface of thewater, or with respect to the buoyant portion or portions of the device.Thus, adjustment of the vertical positioning of the seat portion adjuststhe center of buoyancy of the system based on how far the user is placedin the water. It will be understood that the adjustment of the center ofbuoyancy of the “system” is likely to change more significantly for abuoyancy adjustment than a center of buoyancy of the device alone. Thus,the same device can accommodate users of varying weight and height.

FIG. 1 represents one embodiment of a device that carries a userpartially submerged in the water. Watercraft 100 represents a device asdiscussed above, which holds user 110 to propel user 110 through thewater. It will be understood that the depictions in the figures are notnecessarily representative of actual size or relative dimensions.Rather, the figures are intended to provide examples and illustratecertain features of the invention, and are not intended asspecifications for the design of a water device described herein. Thoseof skill in the art will understand how to implement the descriptionsprovided herein.

Watercraft 100 includes at least one pontoon 120, which is a means toprovide buoyancy to watercraft 100. While a “pontoon” my suggest acertain shape or placement with respect to watercraft 100, it will beunderstood that other flotation mechanisms could be used. Generally, abuoyancy means includes a housing that encloses a substance of densityless than the density of water, typically much less dense. Examples of a“buoyant” substance include air and foam. Thus, pontoon 120 is oneexample of a mechanism that could be used to enclose a buoyant substanceto provide buoyancy to watercraft 100.

Pontoon 120 represents a buoyancy mechanism that could be of a varietyof different shapes or sizes. The illustration in FIG. 1 provides oneexample, which could be modified in a variety of ways. For example, aflotation device could be mostly in front of a user, or mostly behind auser, or mostly to the side of a user. A pontoon to the side of the useris illustrated.

Sitting platform 140 represents one example of a platform or holdingmeans that holds user 110 during operation of watercraft 100. Sittingplatform 140 could be alternatively replaced by a resting or lyingplatform, where a user either reclines, or lays forward on the device.However, for purposes of comfort and ease of use, and for accommodatingusers of different size as well as age and activity level, a sittingplatform provides a good holding mechanism.

Sitting platform 140 (or an alternative platform, which can becollectively referred to as a platform or a riding platform) is attachedto pontoon 120. In one embodiment, the same means or mechanism thatattaches the platform to the buoyant portion of watercraft 100 alsofunctions to adjust the position of the platform relative to the buoyantportion. For example, platform height adjuster 150 adjusts at least thevertical positioning of platform 140 with respect to pontoon 120. Asimple attachment bar could have a height adjustment mechanism built in,such as is known with poles of different sizes, and securing mechanismssuch as tabs, rods, pins, or some other device that can interact withoverlapping holes in telescoping poles.

Water level 160 represents a nominal water level that may be a desiredlevel for operation of watercraft 100. It will be understood that thenominal water level may be made higher or lower depending on a number offactors. For example, certain activities may be more desirable to havethe user “higher” in the water (e.g., less of the user submerged), or“lower” in the water (more of the user submerged). Additionally, theexpected waving of the body of water may suggest having a user higher orlower in the water (e.g., a user may want to be higher in water that hasmore wave activity). Different users may also simply prefer to be higheror tower in the water.

It will be understood that when users of different size and/or weightride watercraft 100, the size and weight of the user will have an affecton where water level 160 comes on the user. This is because watercraft100 has a nominal center of buoyancy, and the center of buoyancy of theuser plus the device will be different than the center of buoyancy ofthe device itself. Thus, watercraft 100 will sit higher or lower in thewater depending on who rides it. Adjusting the vertical distance ofplatform 140 relative to pontoon 120 will adjust the center of buoyancyof the device plus user either higher or lower in the water, whichevereffect is desired.

In addition to adjusting the platform height, or alternatively, otherbuoyancy adjustments could be made, such as adding or removing weight towatercraft 120 (e.g., by adding/removing, objects (weights), sand,water, or some other substance). In certain designs, a bilge pump couldtake on or evacuate water from a hold in watercraft 100 (not explicitlyshown) to adjust the buoyancy.

However buoyancy adjustments are made, the adjustment to buoyancychanges the overall sitting in the water of the device plus user,sitting either higher or lower, depending on the adjustment, relative toprior to the adjustment. Such adjustments can be made for comfort of theuser, and to provide an in-the-water experience for the user.

Propeller 130 represents a propulsion means or propelling mechanism forwatercraft 100. The shape, size, and position of propeller 130 may bedifferent than the example provided in FIG. 1. In one embodiment, amotor is included in pontoon 120, and only a propeller or similarmechanism is where propeller 130 is shown. Alternatively, what is shownas propeller 130 could include the motor and propeller or otherpropulsion mechanism.

In one embodiment, propeller 130 is directly connected to pontoon 120.In another embodiment, propeller 130 is connected to the ridingplatform, which is connected to the buoyancy mechanism.

FIG. 2 represents one embodiment of a flotation portion of a device thatcarries a user partially submerged in the water. Pontoon 200 isprimarily responsible for the buoyancy of the water device. In oneembodiment, pontoon 200 is made of plastic, but could also be made ofwood, metal, or a composite material or other material that wouldprovide the ability to be buoyant. In one embodiment, pontoon 200 is asimple structure that provides buoyancy and provides a location to keepbatteries or fuel to operate the device. In another embodiment, thepontoon itself may be able to adjust its center of buoyancy through theuse of a bilge pump or similar device. The pontoon may additionally oralternatively include regions (not shown) where weights can be attachedto the body of the pontoon or inserted into the body of the pontoon toadjust its buoyancy.

The side view illustrates motor mount 210, which could represent onelocation where the motor may actually be located, or where a motor maybe attached to pontoon 200. Mounts 220 illustrate potential connectionpoints to another pontoon, for a device with parallel pontoons, asdescribed in more detail below with reference to FIGS. 3A and 3B.Although two mounts 220 are illustrated, more or fewer may be used, andthe location is merely exemplary, rather than restrictive.

In one embodiment, the “in the water” device uses an electric motor,powered by one or more batteries. Use of battery power prevents certainundesirable effects of gas-powered motors; namely, heat, noise, andexhaust. However, gasoline (or other fuel) may be used instead ofbattery power. The power source or fuel source needs a location on thewatercraft. As illustrated, one possible location is in the pontoon orpontoons, as shown by battery 230. More detail regarding battery poweris provided below with respect to FIGS. 4A-4C.

FIG. 3 represents one embodiment of a front view of a device thatcarries a user partially submerged through the water, illustrating theseating portion and the propellers. FIG. 3A illustrates a side view oraspect view of one implementation of a watercraft as described herein,while FIG. 3B illustrates a front view of the implementation.

As illustrated, the device includes a parallel pontoon configuration,where two pontoons 310 are connected together. Although illustrated ashaving the pontoons parallel or substantially parallel, there could beimplementations where two pontoons 310 are connected, but converge atone end or another. Pontoons 310 are connected by a crossbar (shown butnot labeled). The crossbar may be positioned somewhere near the nominalwater line. It will be understood that larger pontoons 310 may be usedto carry additional weight, and even hold gear.

For example, a watercraft could be designed to carry scuba gear, andcould even anchor to allow a user to leave the craft. Thus, in additionto riding for leisure, or for sport (e.g., navigating a regatta orcourse, which may include navigating a course as well as shooting atarget with a water gun), the device could be used to carry scuba diversto a dive location. By riding the device through the water, the diverscould avoid having to load and unload gear from a boat, but are notfully submerged, and so can use the full supply of their gear for divetime.

The device includes a seating portion, shown by seat 320, which ismounted on adjustable bar 330 that extends down from the surface of thewater. Thus, the riding platform may be submerged in the water. Bar 330is shown somewhat angled. Different implementations may include more orless angling from perpendicular (perpendicular with respect to a planethat represents the nominal water level). In one embodiment, seat 320 isconsidered to include the bar that extends down into the water. In oneembodiment, the depth of seat 320 is adjustable, for example, byallowing bar 330 to be adjusted in length. Extending the length of thebar (e.g., by having a telescopic bar, or having an outer structure andat least one inner structure having a smaller size (e.g., diameter) thatcan extend out) positions seat 320 further into the water, whileshortening bar 330 brings seat 320 closer to the surface of the water.

As shown, seat 320 is substantially parallel to the surface of the water(or a plane that represents the nominal water level). There could be aslight curve up, such as using a type of bucket seat, or seat 320 mayinclude a portion that extends up and provide back support. Asillustrated, seat 320 allows a user to sit partially submerged while thecraft propels the rider in and through the water. Seat 320 is positionedto allow at least a portion of the user (e.g., head and shoulders) to beabove the nominal water line (while it is understood that a wake, wave,or swell could temporarily alter how much of the user is out of thewater).

Adjusting the depth of seat 320 adjusts the center of buoyancy of thesystem that includes the device and the rider or user. Thus, the devicecould accommodate persons of various weight and height. Althoughspecific ranges of height and weight would vary by design (e.g., lengthof the cross bar, size of the pontoon, depth of the seat, and so forth),basic designs are contemplated in the range of accommodating riders ofapproximately 20-150 kg (approximately 45-300 lbs), and of approximately1.4-2.2 meters (approximately 4′6″-7″. Other designs can be provided forlarger or smaller sizes.

In one embodiment, the angle of seat 320 may be rotationally adjustedwith respect to a plane of the surface of the water allow a user to beinclined further forward or backward (for viewing objects below, such asunder, the water, or for viewing objects above, such as trees, clouds,birds, or other things). In one embodiment, a seating portion mayinclude a back to allow the user to recline. The rotational adjustmentof seat 320 could be set at the dock, and fixed during operation, or maybe adjustable by the user during operation.

As illustrated in FIGS. 3A and 3B, in one embodiment, a watercraft mayinclude two pontoons 310, where each pontoon includes its own propulsion340. Thus, separate motors and/or propellers could be attached to eachpontoon 310. An alternative system could be configured to have a singlemotor with multiple pontoons. Power 350 illustrates one possiblelocation for power for the device, which as illustrated may be locatedin each pontoon.

Each pontoon 310 is shown have a motor with propeller (propulsion 340)to create the thrust that will carry the user through the water. In oneembodiment, each pontoon motor is independently operated, such as bytoggles or other control switches 360. As illustrated, control switches360 may be located near the crossbar. Thus, for example, it is easy fora rider to hold onto the crossbar for stability in operating the craft,and use the toggles to control the craft. Control switches could thus beintegrated into pontoons 310 to control speed and/or direction of thedevice.

The thrust control could also be provided via knob or sliding knob. Anyof the possible mechanisms can allow for slower or faster movement(e.g., pushing a toggle farther forward may provide more thrust thanpushing it less). In one embodiment, the controls may allow forward onlythrust for each pontoons into which they are integrated. In oneembodiment, partial or full reverse thrust may also be possible. Thus,in one embodiment, independent motor control is provided, which allowsgood control and maneuverability of the device, where thrusting the leftpontoon would turn right, thrusting the right pontoon would turn left,and thrusting both would move straight ahead.

FIGS. 4A-4C represent one embodiment of a device that carries a userpartially submerged in the water, illustrating more detail with respectto battery mechanisms. The device configuration of these figures is adual-pontoon design with battery-power. In FIG. 4A, battery compartment410 is closed. In FIG. 4B, battery compartment 420 is open. FIG. 4Cillustrates a closer view of an embodiment of battery compartment 420.Seat 430 and control switches 440 are also seen in FIGS. 4A and 4B.

Battery compartment 410 is the same as battery compartment 420, exceptthat battery compartment 410 includes covers over the compartments,which battery compartment 420 is open. As mentioned above, other formsof power may be used (e.g., fuel), hut may be less preferred from asafety and usability perspective. In one embodiment, the batteries allowfor easy removal and replacement, which can ease in the maintenance ofthe device. Thus, a device may be operated for a time, and then thebattery covers removed, the batteries replaced with fully chargedbatteries, and the other batteries can be charged while the device iscontinued to be used. The removal and installation of the batteries canbe performed by a trained individual in a matter of minutes.

FIGS. 5A-5B represent one embodiment of a device that carries a userpartially submerged in the water, and having a water gun attachment. Asmentioned above, in one embodiment, a device that moves a rider throughthe water can have a water gun or water cannon attachment, which drawswater from below the surface of the water 520 and pumps it to a nozzleabove the surface of the water to eject the water. FIG. 5A illustrates aside view, and FIG. 5B illustrates a side view.

As shown in FIG. 5A, water cannon 530 (also referred to as a water gun)may be mounted on crossbar 540 that arches over the water and betweentwo pontoons 510. It may simply be mounted atop a bar or mount in asingle pontoon configuration. Water cannon 530 could include a pumpattached up near or on the crossbar or at the mounting location of thewater gun. In one embodiment, water cannon 530 is attached not on across bar, but on pontoon 510, perhaps raised slightly off the topsurface of the pontoon. For higher-powered water cannons (e.g., somecannons can fire a stream of water approximately 10 meters(approximately 30 feet)), there may be advantage to having the cannonmounted on a bar or a raised mount to prevent firing on otherindividuals at close range. The cannon may also be mounted to bepositioned at an upward angle to prevent firing at people or animals atclose range that may cause injury.

While the water may be drawn from near the front of pontoon 510, forwater cannon 530 near the front of the device, water cannon 530 couldalternatively be positioned near the back of the device. The water maynot necessarily be drawn from the same half of the device where thecannon is mounted (a cannon in the front could draw water from the back,or a cannon in back could draw water from the front). Water pump 550shows alternative locations of where a pump may be mounted to providethe pressurization to expel the water from water cannon 530. Namely,pump 550 may be on the rider side of the pontoon (not shown), on theside of the pontoon away from the user (as shown), or mounted near thewater cannon. At least some tubing or pipe or other mechanism or thepump itself needs to be in the water to allow pump 550 to draw water upto water cannon 530. The water may be fed to water cannon 530 through atube or pipe, which may include tubing that runs through a crossbar ormounting bar or stand.

A water cannon or similar device may be connected to one or both sidesof the device, such as one water cannon on each pontoon 510. The watercannon can draw water through a pump or tube from the side of a pontoon,which is then compressed or pressurized to expel out the end or nozzlein a stream. In one embodiment, the device includes a water cannon oneach pontoon. In another embodiment, only a single water cannon isprovided.

FIGS. 6A-6B represent one embodiment of a device that carries a userpartially submerged in the water, and having an underwater viewingportion. FIG. 6A illustrates a side view of a device with viewer 620 forviewing into the water. FIG. 6B illustrates a side view of the devicewith viewer 620. It will be understood that any of a great number ofconfigurations for viewer 620 could be used, and one non-limitingexample is shown.

Water level 610 indicates a nominal water level, and viewer 620 includesportions above and below water level 610. Viewer 620 is shaped todisplace the water to allow a user to look down on viewer 620 from abovethe surface of the water to see into the water. It is understood thatrefraction prevents clear viewing into the water from above it, which isgenerally even true in locations known for having clear waters. However,by displacing the water at the surface with a transparent or clearviewing device that extends down into the water, a user can generallysee much more clearly into the water. Thus, viewer includes a portionabove water level 610, and clear portion 630 that extends below thesurface of the water.

Mounts 640 may hold viewer 620 to the device, or other mounting systemswill be understood. Clear portion 630 may be, for example, a clearplastic or acrylic device mounted to allow the user to look down intothe water while keeping the head and shoulders above the water. Such anexperience may provide some of the enjoyment of snorkeling withouthaving to place the individual's face into the water.

It will be understood that examples and descriptions related todifferent mechanisms and devices describe means for providing any of thefunctions described as being associated with them. For example, andsitting or riding means provides functions related to holding a user,adjusting a sitting position (e.g., upright versus reclined), supportinga user, or other functions. Buoyancy means provide functions related toproviding flotation. In conjunction with buoyancy adjustment means,functions related to adjusting the center of buoyancy may be provided bybuoyancy means and buoyancy adjustment means. There may be motors orpropellers as described or any known in the art to provide the functionsrelated to propulsion or moving a user through the water.

Besides what is described herein, various modifications may be made tothe disclosed embodiments and implementations of the invention withoutdeparting from their scope. Therefore, the illustrations and examplesherein should be construed in an illustrative, and not a restrictivesense. The scope of the invention should be measured solely by referenceto the claims that follow.

1. A watercraft for use in water comprising: a riding platform toreceive a user, and positioned to hold the user partially submerged inthe water; a pontoon connected to the riding platform to providebuoyancy to the watercraft, the user and the watercraft together havinga center of buoyancy in the water; a buoyancy adjustment mechanism toadjust the center of buoyancy, to adjust for users of different size, toprovide a center of buoyancy that maintains the user partially submergedin the water, with at least the user's head above the surface of thewater, and at least the user's legs below the surface of the water; anda motor connected to the pontoon to propel the watercraft through thewater with the user partially submerged.
 2. The watercraft of claim 1,wherein the riding platform comprises a seat submerged in the water. 3.The watercraft of claim 2, wherein the seat includes a portionsubstantially parallel to the surface of the water, and a back againstwhich the user's back is to rest.
 4. The watercraft of claim 1, whereinthe pontoon comprises a first pontoon, and further comprising: a secondpontoon parallel to, and connected to the first pontoon via a crossbar.5. The watercraft of claim 4, further comprising: a propeller connectedto each pontoon, each propeller being separately controllable.
 6. Thewatercraft of claim 1, wherein the buoyancy adjustment mechanismcomprises a bar connecting the riding platform to the pontoon, the barbeing adjustable to increase or decrease a vertical distance between theriding platform and the pontoon.
 7. The watercraft of claim 1, whereinthe motor is connected to the pontoon via being connected to the ridingplatform.
 8. The watercraft of claim 1, further comprising: a controlswitch integrated into the pontoon to control speed and/or direction ofthe watercraft.
 9. The watercraft of claim 1, further comprising: aviewing window connected to the pontoon, shaped to displace the water,having a portion above the water and a portion below the water, theviewing window including at least a portion below the water that istransparent to allow the user to see into the water from above thewater's surface.
 10. The watercraft of claim 1, further comprising: awater cannon attached to the pontoon, having a pump to draw water frombelow the surface of the water, and a nozzle above the surface of thewater to eject the water.
 11. An apparatus for moving a user in thewater, comprising: means for riding, the means positioned on theapparatus for holding a user partially submerged in the water whileoperating the apparatus; means for providing buoyancy, connected to themeans for riding, for providing buoyancy to the combination of user andwatercraft, where the user and the watercraft together having a centerof buoyancy relative to a surface of the water; means for adjusting thecenter of buoyancy for adjusting the buoyancy of the combination of userand watercraft, to adjust for users of different size, to adjust thecenter of buoyancy relative to the surface of the water to maintain theuser partially submerged in the water, with at least the user's headabove the surface of the water, and at least the user's legs below thesurface of the water; and means for propelling the combination of userand apparatus with the user partially submerged in the water.
 12. Theapparatus of claim 11, wherein the means for riding comprises means fora user sitting partially submerged in the water.
 13. The apparatus ofclaim 12, wherein the means for sitting includes means for supporting auser's back sitting in a substantially upright position.
 14. Theapparatus of claim 11, wherein the means for providing buoyancycomprises: a pair of parallel buoyancy means connected together via acrossbar.
 15. The apparatus of claim 14, wherein the means forpropelling comprises a pair of propulsion means, one in each of the pairof parallel buoyancy means, each propulsion means being separatelycontrollable.
 16. The apparatus of claim 11, wherein the means foradjusting the center of buoyancy comprises means for adjusting avertical distance of means for riding relative to the means forproviding buoyancy.
 17. The apparatus of claim 11, further comprising:means for controlling speed of the apparatus integrated into the meansfor providing buoyancy.
 18. The apparatus of claim 11, furthercomprising: means for controlling direction of the apparatus integratedinto the means for providing buoyancy.
 19. The apparatus of claim 11,further comprising: means for underwater viewing connected to the meansfor providing buoyancy, including at least a portion below the waterthat is transparent to allow the user to see into the water from abovethe water's surface.